Pharmaceutical composition for treating scars on the skin, and method for treating scars on the skin using same

ABSTRACT

The present invention relates to a pharmaceutical composition for treating scars on the skin, comprising a mixture of botulinum toxin and air. The mixture of botulinum toxin and air according to the present invention, when injected in the dermis, may temporarily removed the elasticity of the dermis and flatten out the depressed part of the scar, and thus enables elaborate intradermic resection and increases the therapeutic effects of lasers for treating pulsed dye laser or of fractional lasers. Thus, scars on the skin can be effectively improved through a one-time operation without negatively affecting the daily lives of patients.

TECHNICAL FIELD

The present invention relates to a pharmaceutical composition fortreating skin scars, comprising a mixture of botulinum toxin and air,and a method for treating skin scars using the same.

BACKGROUND ART

Skin protects the body's organs from external environmental threats andacts as a thermostat to maintain body temperature. The skin consists ofseveral different layers, each with a specialized function. The majorlayers include the epidermis, the dermis and the hypodermis. Theepidermis is a stratifying layer of epithelial cells that overlies thedermis, which consists of connective tissue. Both the epidermis and thedermis are further supported by the hypodermis, an internal layer ofadipose tissue.

The epidermis, the topmost layer of skin, is only 0.1 to 1.5 millimetersthick (Inlander, Skin, New York, N.Y.: People's Medical Society, 1-7(1998)). It consists of keratinocytes and is divided into several layersbased on their state of differentiation. The epidermis can be furtherclassified into the stratum corneum and the viable epidermis, whichconsists of the granular melphigian and basal cells. The stratum corneumis hygroscopic and requires at least 10% moisture by weight to maintainits flexibility and softness. The hygroscopicity is attributable in partto the water-holding capacity of keratin. When the stratum corneum losesits softness and flexibility, it becomes rough and brittle, resulting indry skin. The dermis, which lies just beneath the epidermis, is 1.5 to 4millimeters thick. It is the thickest of the three layers of the skin.In addition, the dermis is also home to most of the skin's structures,including sweat and oil glands (which secrete substances throughopenings in the skin called pores, or comedos), hair follicles, nerveendings, and blood and lymph vessels (Inlander, Skin, New York, N.Y.:People's Medical Society, 1-7 (1998)). However, the main components ofthe dermis are collagen and elastin. The hypodermis is the deepest layerof the skin. It acts both as an insulator for body heat conservation andas a shock absorber for organ protection (Inlander, Skin, New York,N.Y.: People's Medical Society, 1-7 (1998)). In addition, the hypodermisalso stores fat for energy reserves. The pH of skin is normally between5 and 6. This acidity is due to the presence of amphoteric amino acids,lactic acid, and fatty acids from the secretions of the sebaceousglands. The term “acid mantle” refers to the presence of thewater-soluble substances on most regions of the skin. The bufferingcapacity of the skin is due in part to these secretions stored in theskin's stratum corneum.

Botulinum toxins (also known as botulin toxins or botulinum neurotoxins)are neurotoxins produced by the gram-positive bacteria Clostridiumbotulinum. They act to produce paralysis of muscles by preventingsynaptic transmission or release of acetylcholine across theneuromuscular junction, and are thought to act in other ways as well.Their action essentially blocks signals that normally would cause musclespasms or contractions, resulting in paralysis. Botulinum toxin isclassified into eight neurotoxins that are serologically related, butdistinct. Of these, seven can cause paralysis, namely botulinumneurotoxin serotypes A, B, C, D, E, F and G. Each of these isdistinguished by neutralization with type-specific antibodies.Nonetheless, the molecular weight of the botulinum toxin proteinmolecule, for all seven of these active botulinum toxin serotypes, isabout 150 kD. The botulinum toxins released by the bacterium arecomplexes comprising the 150 kD botulinum toxin protein molecule inquestion along with associated non-toxin proteins. The botulinum toxintype A complex can be produced by Clostridia bacterium as 900 kD, 500 kDand 300 kD forms. Botulinum toxin types B and C are apparently producedas only a 700 kD or 500 kD complex. Botulinum toxin type D is producedas both 300 kD and 500 kD complexes. Botulinum toxin types E and F areproduced as only approximately 300 kD complexes. The complexes (i.e.molecular weight greater than about 150 kD) are believed to contain anon-toxin hemaglutinin protein and a non-toxin and non-toxicnonhemaglutinin protein. These two non-toxin proteins may act to providestability against denaturation to the botulinum toxin molecule andprotection against digestive acids when toxin is ingested. Additionally,it is possible that the larger (greater than about 150 kD molecularweight) botulinum toxin complexes may result in a slower rate ofdiffusion of the botulinum toxin away from a site of intramuscularinjection of a botulinum toxin complex. The different serotypes ofbotulinum toxin vary in the animal species that they affect and in theseverity and duration of the paralysis they evoke. For example, it hasbeen determined that botulinum toxin type A is 500 times more potent, asmeasured by the rate of paralysis produced in the rat, than is botulinumtoxin type B. Additionally, botulinum toxin type B has been determinedto be non-toxic in primates at a dose of 480 U/kg, about 12 times theprimate LD₅₀ for type A. Due to the molecular size and molecularstructure of botulinum toxin, it cannot cross the stratum corneum andthe multiple layers of the underlying skin architecture.

Botulinum toxin type A is said to be the most lethal natural biologicalagent known to man. Spores of C. botulinum are found in soil and cangrow in improperly sterilized and sealed food containers. Ingestion ofthe bacteria can cause botulism, which can be fatal.

Meanwhile, a scar is a mark left on the skin after it heals, and inparticular, a depressed scar is a pathological response of the skin suchas dermal damage or fibrosis after an injury of the epidermis. Treatmentmethods of depressed scars include dermabrasion for removing the skinlayer of damaged area using laser irradiation or various compounds orusing a dermabrator, subcision (elevating the bottom of the dermis) forincreasing the height of the depressed scar. However, in the case ofdermabrasion, it affects the daily life, and the effect of filling thescar is reduced, and in the case of subcision, the effect of preciselyadjusting the height of the scar is reduced due to fibrosis on theboundary of the scar, leading to unsatisfactory cosmetic results aftersurgical procedure.

The muscle-paralyzing effects of botulinum toxin have been used fortherapeutic effects on various conditions such as hemifacial spasm,adult onset spasmodic torticollis, anal fissure, blepharospasm, cerebralpalsy, cervical dystonia, migraine headaches, strabismus,temperomandibular joint disorder, and various types of muscle crampingand spasms. More recently, the muscle-paralyzing effects of botulinumtoxin have been taken advantage of in therapeutic and cosmetic facialapplications such as treatment of wrinkles, frown lines, and otherresults of spasms or contractions of facial muscles. However, noresearch on the treatment of scars using botulinum toxin has beenreported, and in particular, no method for effectively treating skinscars by preparing botulinum toxin in the form of a mixture andinjecting the mixture in a skin-specific manner has been reported.

Therefore, if the problems of existing scar treatment methods can besolved using botulinum toxins which have been used in the treatment ofvarious diseases, the botulinum toxin can be effectively used in thetreatment of skin scars, and thus research on a new composition fortreating skin scars using botulinum toxin and a method for treating skinscars is urgently required.

DISCLOSURE Technical Problem

The present inventors have studied methods for treating skin scars usingbotulinum toxin and found that when a mixture of botulinum toxin and airis injected into the dermis, it removes the elasticity of the dermis andelevates a depressed scar to effectively increase the effect of treatingskin scars, thus completing the present invention.

Therefore, an object of the present invention is to provide apharmaceutical composition for treating skin scars, comprising a mixtureof botulinum toxin and air, and a method for treating skin scars usingthe same.

Technical Solution

To achieve the above object, the present invention provides apharmaceutical composition for treating skin scars, comprising a mixtureof botulinum toxin and air.

Another object of the present invention is to provide a method fortreating skin scars, comprising injecting the composition into thedermis.

Advantageous Effects

According to the mixture of botulinum toxin and air of the presentinvention, when it is injected into the dermis, the elasticity of thedermis is temporarily removed and the depressed scar is elevated, whichallows subcision to be precisely performed and increases the therapeuticeffect of pulsed dye laser or fractional laser, thus effectivelytreating skin scars with only one surgical procedure without affectingthe daily life.

DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing the comparison of the effects of treatingskin scars before surgical procedure (A) and 6 months after injecting acomposition of the present invention and performing subcision once (B).

FIG. 2 is a diagram showing the comparison of the effects of treatingskin scars before surgical procedure (A) and 6 months after injecting acomposition of the present invention and performing subcision threetimes (B).

FIG. 3 is a diagram showing depressed scars in five areas on the leftand right faces of a patient.

FIG. 4 is a diagram showing the comparison of the effects of treatingskin scars depending on the mixture ratio of botulinum toxin and air(volume ratios of 1:1, 1:2, and 1:3).

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention provides a pharmaceutical composition for treatingskin scars, comprising a mixture of botulinum toxin and air.

When the mixture of botulinum toxin and air is injected into the dermis,the elasticity of the dermis is temporarily removed and the depressedscar is elevated, which allows subcision to be precisely performed andincreases the therapeutic effect of pulsed dye laser or fractionallaser, thus effectively treating skin scars with only one surgicalprocedure without affecting the daily life.

In the present invention, the term “botulinum toxin” refers to amolecule that has the biological activity of botulinum toxin and may bea protein, polypeptide, peptide, fusion protein, truncated protein,chimeric protein, mutant protein, or recombinant protein.

The biological activity of the toxin refers, within the context of thepresent invention, to muscular paralysis or inhibition of exocytosis, inparticular, inhibition of exocytosis of acetylcholine or otherneurotransmitters.

Pure or substantially pure botulinum neurotoxin can be obtained from aprotein complex containing botulinum toxin, for example according to themethod described in the literature (Current topics in Microbiology andImmunology (1995), 195, p. 151-154). Pure or substantially purebotulinum neurotoxin can be obtained, for example, by purification of afermentation medium or culture broth containing Clostridium botulinumstrain and can be enriched, for example, with meat or protein-rich food.

The botulinum toxin may comprise at least one selected from the groupconsisting of botulinum toxin serotypes A, B, C, D, E, F and G and maycomprise both Dysport® and Botox®, botulinum neurotoxin Type A productswithout limitation. Moreover, Myoblock®, a botulinum toxin Type Bproduct, may be included in the botulinum toxin.

The botulinum toxin and air may be mixed in a volume ratio of 1:0.1 to1:10 to prepare a pharmaceutical composition for treating skin scars andmay preferably be mixed in a volume ratio of 1:2 to 1:4.

The composition of the present invention may be used in various formsfor the treatment of scars and may be used for pretreatment of subcisionfor the purpose of removing the elasticity of the dermis and elevatingthe depressed scar.

The composition of the present invention may further compriseappropriate carrier, excipient, and diluent which are generally used inthe preparation of pharmaceutical compositions.

The composition of the present invention may preferably be formulated inthe form of liquid, aerosol, and sterile injection, and most preferably,the mixture of botulinum toxin and air may be formulated in the form ofaerosol. When the composition is formulated, diluents or excipients suchas fillers, extenders, binders, wetting agents, disintegrants,surfactants, etc. may be used.

The composition of the present invention may optionally comprise adispersant. As used herein, the dispersant refers to any substance oradditive capable of preventing or minimizing undesired or uncontrolledagglomeration between the botulinum toxin and the carrier of the presentinvention. The dispersant is useful when a concentrated botulinum toxinsolution is to be employed due to capacity limit, for example. In thesecases, the dispersant allows the botulinum toxin to be dispersed, thuspreventing the agglomeration of toxins which may occur in the absence ofthe dispersant. In general, the dispersant (1) is non-irritating, (2)does not destroy the botulinum toxin, (3) does not cause an increase inpermeability, (4) has a reliable and stable particle size, (5) does nothave a charge, and (6) does not interfere with complexes of toxins andtransdermal carriers.

The injection of the present invention refers to the administration of apredetermined composition of the present invention to a subject by anysuitable route.

The preferred dosage of the pharmaceutical composition of the presentinvention depends on the scar condition and weight of a patient, theseverity of disease, the type of drug, the route and duration ofadministration, etc., but may be appropriately selected by those skilledin the art. For the desired effect, the composition of the presentinvention may be administered in an amount of 0.1 unit to 3000 units perinjection, preferably 1 unit to 10 units, based on the content ofbotulinum toxin type A. The composition of the present invention may beadministered once or several times a day.

The composition of the present invention may be used alone or inconjunction with surgery, radiation therapy, hormone therapy, chemicaltherapy, and methods using biological response modifiers for thetreatment of skin scars and may preferably be used in conjunction withpulsed dye laser or fractional laser, and subcision.

Moreover, the present invention provides an aerosol spray kit comprisingthe composition formulated in the form of aerosol.

The present invention provides a kit comprising a device for injectionthe botulinum toxin into the skin as well as a liquid, gel, cream, etc.suitable for use in the skin or epithelium of a subject. The kit foradministration of the composition of the present invention under theinstructions of a medical practitioner or by a patient or subject maycomprise a custom applicator suitable for its purpose.

Moreover, the present invention provides a method for treating skinscars, comprising the steps of:

(1) removing the elasticity of the dermis of wounded skin by injecting amixture of botulinum toxin and air into the dermis through a syringeneedle of 28 gauge to 31 gauge; and

(2) performing at least one surgical procedure selected from the groupconsisting of subcision, pulsed dye laser, and fractional laser on thedermis whose elasticity is removed in step (1).

The method of the present invention will be described in more detailstep by step.

Step (1) is to remove the elasticity of the dermis of wounded skin byinjecting a mixture of botulinum toxin and air, in which the botulinumtoxin and air are mixed in a volume ratio of 1:0.1 to 1:10, preferably1:2 to 1:4 and injected into a depressed scar of a subject's skin.

The injection may be performed by administering the mixture using asyringe needle of 28 gauge to 31 gauge, and the mixture may preferablybe sprayed through a syringe needle of 31 gauge and may be sprayed andinjected into the skin scar at a very high pressure by Bernoulli's fluiddynamics. Moreover, a BD insulin syringe with a syringe needle of 28gauge to 31 gauge may be used.

The injection may preferably be performed by spraying the composition inthe form of aerosol.

Step (2) is to additionally perform at least one surgical procedureselected from the group consisting of subcision, pulsed dye laser, andfractional laser after injecting the mixture of botulinum toxin and air.

The subcision may be performed on the dermis whose elasticity istemporarily removed by injecting the mixture of step (1), thus preciselyadjusting the height of the scar.

The pulsed dye laser or fractional laser may have a synergistic effecton the treatment of skin scars together with the therapeutic effect ofthe mixture of botulinum toxin and air.

Mode for Invention

Hereinafter, the present invention will be described in detail withreference to Examples. However, the following Examples are merelyillustrative of the present invention and the present invention is notlimited by the following Examples.

Example 1 Preparation of Composition Mixed with Botulinum Toxin and Air

0.5 U/cc botulinum toxin solution was prepared by adding 10 cc salinesolution to a bottle containing 50 U Botox, a botulinum toxin Type A1,and diluting the resulting mixture. The prepared botulinum toxinsolution was loaded in a BD Ultra-Fine™ II Short Needle Insulin Syringe3/10 cc 31 G×8 mm (5/16 in), and the atmospheric air was filled in thecorresponding syringe to prepare a mixture of botulinum toxin and air.At this time, the botulinum toxin and air were mixed in a volume ratioof 1:1, 1:2, 1:3, and 1:4, respectively.

In order to compare the effects of the prepared compositions on thetreatment of scars, control groups treated with air only and treatedwith botulinum toxin only were established in the following Examples.

Example 2 Determination of Treatment of Skin Scars

The composition (mixed with 0.03 cc botulinum toxin and 0.12 cc air)prepared in Example 1 was administered to the dermis of five patientswith actual scars, and the subcision was performed to determine theeffects of treating skin scars. The subcision was performed once orthree times, and the appearance of skin scars after 6 months from thesubcision was compared to the appearance of skin scars before thesubcision.

The results are shown in FIGS. 1 and 2.

As shown in FIGS. 1 and 2, as a result of performing the method fortreating skin scar according to the present invention, all patients withskin scars showed significant therapeutic effects, and the treatmentsatisfaction was more than 80% with only one surgical procedure,indicating that the patients' satisfaction was very high.

Example 3 Comparison of Effects of Treating Skin Scars Depending on theMixture Ratio of Botulinum Toxin and Air

In order to numerically determine the effects of treating skin scar,which were determined with the naked eye in Example 2, atmospheric aircontaining no botulinum toxin, botulinum toxin containing no air, andcompositions mixed with botulinum toxin and air in volume ratios of 1:1,1:2 and 1:3 were injected into patient's atrophic scars, which were thentreated with pulsed dye laser and fractional laser. More specifically,in order to eliminate analytical errors due to individual differences inthe restoration of scars, five depressed scar areas were selected fromthe left and right faces of each patient (FIG. 3), the mixedcompositions were injected into the corresponding areas, and the effectsof treating scars were quantified. For the quantification of the degreeof treating depressed scars, the 3D LifeViz II™ (Quantificare, France)for numerically measuring the face by three-dimensional analysis wasused.

The results are shown in FIG. 4 and Table 1.

TABLE 1 BTX (Botulinum toxin) AT (Air) BTX:AT = 1:1 BTX:AT = 1:2 BTX:AT= 1:3 Perimeter 38.53 Perimeter 39.8 Perimeter 34.63 Perimeter 32.86Perimeter 35.79 Surface 85.5 Surface 75.72 Surface 69.62 Surface 54.18Surface 66.54 Volume 307.8 Volume 124.36 Volume 79.99 Volume 57.1 Volume132.13 Vol- 307.8 Vol- 124.36 Vol- 79.99 Vol- 57.1 Vol- 132.13 ume > 0ume > 0 ume > 0 ume > 0 ume > 0 Vol- 0 Vol- 0 Vol- 0 Vol- 0 Vol- 0 ume <0 ume < 0 ume < 0 ume < 0 ume < 0 Av Deep 3.6 Av Deep 1.64 Av Deep 1.15Av Deep 1.05 Av Deep 1.99 Minimum 0 Minimum 0 Minimum 0 Minimum 0Minimum 0 Maximum 0 Maximum 0 Maximum 0 Maximum 0 Maximum 0 Rugosity 3.6Rugosity 1.64 Rugosity 1.15 Rugosity 1.05 Rugosity 1.99 After treatmentPerimeter 40.02 Perimeter 36.03 Perimeter 42.67 Perimeter 39.26Perimeter 38.18 Surface 82.73 Surface 59.68 Surface 95.82 Surface 83.55Surface 82.42 Volume 340.78 Volume 135.3 Volume 185.68 Volume 204.93Volume 209.04 Vol- 340.78 Vol- 135.3 Vol- 185.68 Vol- 204.93 Vol- 209.04ume > 0 ume > 0 ume > 0 ume > 0 ume > 0 Vol- 0 Vol- 0 Vol- 0 Vol- 0 Vol-0 ume < 0 ume < 0 ume < 0 ume < 0 ume < 0 Av Deep 4.12 Av Deep 2.27 AvDeep 1.94 Av Deep 2.45 Av Deep 2.54 Minimum 0 Minimum 0 Minimum 0Minimum 0 Minimum 0 Maximum 0 Maximum 0 Maximum 0 Maximum 0 Maximum 0Rugosity 4.12 Rugosity 2.27 Rugosity 1.94 Rugosity 2.45 Rugosity 2.54Volume 1.107147498 1.087970408 2.321290161 3.588966725 1.582078256increase rate

As shown in FIG. 4, the difference in the numerical values of thedepressed scars treated with atmospheric air alone as the control andtreated with the mixture of botulinum toxin and air could be determinedusing the 3D LifeViz II™. In particular, as shown in table 1, thecomparison of the elevations of depressed scars treated with thecompositions mixed with botulinum toxin and air in volume ratios of 1:1,1:2 and 1:3 and those of the control groups showed that the increase inthe volume ratio in the control group treated with botulinum toxin alonewas 1.0, and that in the control group treated with air alone was 1.1,indicating that there was almost no effect of treating depressed scars.However, in the case of the compositions mixed with botulinum toxin andair, the increase in the volume ratio was 1.5 times to 3.5 times, whichmeant that the depressed scars were elevated within a short time,indicating that there were significant effects of treating skin scars.

Hereinafter, formulation examples for the composition of the presentinvention will be illustrated.

Formulation Example 1 Pharmaceutical Composition

1.1 Preparation of Injection

Mixture of botulinum toxin and air of the present 10 mg inventionMannitol 180 mg  Sterile distilled water for injection 2974 mg Na₂HPO₄•2H₂O 26 mg

An injection is prepared with the above ingredients per ampoule (2 ml)according to a conventional method for preparing injections.

1.2 Preparation of Liquid Formulation

Mixture of botulinum toxin and air of the present 10 mg inventionIsomerized sugar 10 g Mannitol  5 g Purified water Proper quantity

A liquid formulation is prepared according to a conventional method forpreparing liquid formations by dissolving each ingredient in purifiedwater, adding a proper quantity of lemon flavor, mixing the ingredients,adding purified water to the resulting mixture to regulate the totalmixture to 100 ml, filling the mixture in a brown bottle, andsterilizing the mixture.

1. A pharmaceutical composition for treating skin scars, comprising amixture of botulinum toxin and air.
 2. The pharmaceutical composition ofclaim 1, wherein the botulinum toxin comprises at least one selectedfrom the group consisting of botulinum toxin serotypes A, B, C, D, E, Fand G.
 3. The pharmaceutical composition of claim 1, wherein thebotulinum toxin and air are mixed in a volume ratio of 1:0.1 to 1:10. 4.The pharmaceutical composition of claim 1, wherein the composition isused for pretreatment of subcision.
 5. The pharmaceutical composition ofclaim 1, wherein the composition removes the elasticity of the dermis.6. The pharmaceutical composition of claim 1, wherein the composition isformulated in the form of aerosol.
 7. An aerosol spray kit comprisingthe composition of claim 1 formulated in the form of aerosol.
 8. Amethod for treating skin scars, the method comprising the steps of: (1)removing the elasticity of the dermits of wounded skin by injecting amixture of botulinum toxin and air into the dermis through a syringeneedle of 28 gauge to 31 gauge; and (2) performing at least one surgicalprocedure selected from the group consisting of subcision, pulsed dyelaser, and fractional laser on the dermits whose elasticity is removedin step (1).
 9. The method of claim 8, wherein the botulinum toxin andair are mixed in a volume ratio of 1:0.1 to 1:10.
 10. The method ofclaim 8, wherein a depressed scar of the wounded skin is elevated by theinjection of step (1).
 11. The method of claim 8, wherein the injectionof step (1) is performed by spraying the composition in the form ofaerosol.